A passer-by said there was a Bay Dreams park-and-ride bus stop "teeming with people" across the road an unmanned Gull service station.
He understood a person had been taken away in an ambulance after collapsing.
An ambulance and a police car were at the scene.
A Fire and Emergency New Zealand spokesman said it was a medical event, so he would not comment.
A Bay Dreams spokeswoman declined to comment, and the Bay of Plenty Regional Council - the organisation that operates buses in Tauranga - directed questions to Bay Dreams organisers responsible for traffic management and additional bus services for the event.
Paramedics were called to the Pāpāmoa Beach Rd incident at 2.39pm. Three ambulances were sent, a spokeswoman for St John said.
A police spokesperson said it appeared the person had been found "seriously ill" on the side of the road by a person who called 111.
The circumstances of how the two people came to be ill are not known, but the incidents come on one of the busiest days of the year for Pāpāmoa and Mount Maunganui.
Some 30,000 people are expected to attend the sold-out Bay Dreams music festival at Trustpower Stadium, with up to 27,000 coming from out of town.
Huge queues formed at the venue this morning as festival-goers waited for the gates to open.
The streets surrounding the stadium and public transport hubs are swarming with people. Some roads are closed and others have reduced speeds, and police have been out in force.
More than 30,000 people are expected to head to Bay Dreams at Trustpower Stadium in Mount Maunganui today.
Huge queues formed at the venue this morning as festival-goers waited for the gates to open.
Free buses have been put on for ticket-holders, with park-and-ride stations in Parton Road, Kawaka St, the CBD and Toi-Ohomai's Windermere campus.
